1. Field of the Invention
The present invention relates to wind turbines, and more particularly, to transporting wind turbines on railroad cars.
2. Background
Wind turbines are used to generate electrical power, and conventional wind turbine 1 is illustrated in FIG. 1. The turbine 1 is mounted on the ground 5 and includes a tower 6 comprised of a plurality of sections with a nacelle 10 mounted on top. A rotor 12 is affixed to the front of the nacelle 10 and blades 14 are connected to the rotor 12. The tower 6 is comprised of sections including base member 16, intermediate members 17 and a top member 18.
Turning now to FIG. 2 the components of nacelle 10 of a conventional wind turbine 1 are illustrated. The nacelle 10 is rotatably mounted on the upper flange 15 of the top tower member 18 through a bearing 19 having an inner race and outer race connected to flange 15. The inner race of the bearing 19 is connected to an annular nacelle mounting plate 20 having a larger diameter than the outer diameter of the top tower member 18.
The nacelle 10 has a cylinder-like configuration extending horizontally and both ends are closed. The nacelle 10 includes a front nacelle section 21A and a rear nacelle section 21B. The nacelle 10 has holes 22 and 23 disposed opposite to each other on the upper and lower surfaces thereof, respectively. The hole 22 provided on the upper surface of the nacelle 10 is closed by a lid 22a, after the nacelle 21 is mounted on the tower 6.
A front supporting member 24 and rear supporting member 25 are installed on the floor surface of the front nacelle section 21a and rear nacelle section 21b. The respective supporting members 24, 25 are connected through a plurality of L-shaped mounting members 26 with the mounting plate 20. In the front nacelle section 21A a rotation shaft 32 for supporting a rotor hub 31, a bearing box 33 for supporting the rotation shaft 32, a gear box 34 for changing the revolution speed of the rotation shaft 32, a brake 35 and a shaft 36, are disposed.
In the rear nacelle section 21B a generator 37 connected to the shaft 36, a controller 38, and hydraulic power sources 39 are disposed. A drive shaft 40 is disposed between the gear box 34 and the generator 37 to transmit power from the gear box 34 to the generator 37. A yaw motor 41 is mounted on the nacelle mounting plate 20 in order to rotate the nacelle 10. An output shaft of the yaw motor 41 is provided with a drive gear (not shown) and the drive gear meshes with the gear formed on the outer periphery of the outer race of the bearing 19 so that the rotation of the yaw motor 41 adjusts the direction of the nacelle 10.
Various components of a wind turbine are often manufactured in different parts of the world and then transported to a site and assembled and erected at the site. As one example, a manufacturer who wishes to assemble a tower in the United States may have the towers manufactured in Korea, the nacelles manufactured in Denmark and the blades manufactured in Germany. The components are shipped by ocean liners to the US and then loaded onto railroad cars and/or trucks for transportation to the assembly site where they are erected. Some types of wind turbines are relatively large structures which have some fragile components, and therefore they must be transported carefully to avoid damage.
Cargo containers, sometimes called intermodal containers, are commonly used for transportation of goods by a variety of methods. Such cargo containers are designed for shipment by ship, railroad and truck so that the cargo can be packed into the container at the beginning of the trip and then transported to the destination by more than one mode of transportation with out the need to load and unload the container when changing from one transportation mode to another. A conventional intermodal cargo container is taught in U.S. Pat. No. 4,782,561.
As described in U.S. Pat. No. 4,782,561 the intermodal cargo containers each have eight corners, and mounted on each corner is a corner fitting which includes three standard sized and shaped slots, one at each face of the container. The corner fittings cooperate with twist locking devices which enable a user to connect and disconnect the corners of a container to corresponding corners of another container thus permitting two containers to be connected to one another in a stable manner during transit and then disconnected from each other as required.